Gastric erosion, peptic ulcers and stomach cancer can cause someone to vomit blood, according to WebMD, Mayo Clinic and the American Cancer Society. All three conditions also cause pain and digestive problems.
Stomach cancer is difficult to diagnose in its early stages, claims the American Cancer Society. When it presents with symptoms, they can mimic other, less dangerous conditions, such as ulcers or viral infections. Along with vomiting blood, the patient can also experience abdominal pain or a vague abdominal discomfort, unexplained weight loss, poor appetite, and nausea. He may feel full after eating even a small meal. His abdomen may be swollen from the build-up of fluid, and he may be anemic.
A peptic ulcer is a sore in the lining of the stomach, duodenum or esophagus, according to Mayo Clinic. The most prominent symptom is a burning pain which is made worse by gastric juices. The pain may be worse when the stomach is empty and is eased by eating or taking antacids. The pain may also flare up at night, then disappear for long stretches of time. Besides vomiting blood, other symptoms may be black, tarry stools, a disturbed appetite and unintended weight loss.
Gastritis is the inflammation or erosion of the stomach lining, according to WebMD. Symptoms besides vomiting blood are abdominal bloating and pain, nausea, indigestion, hiccups and loss of appetite.